hugetlb: allow arch overridden hugepage allocation

Allow alloc_bootmem_huge_page() to be overridden by architectures that
can't always use bootmem.  This requires huge_boot_pages to be available
for use by this function.

This is required for powerpc 16G pages, which have to be reserved prior to
boot-time.  The location of these pages are indicated in the device tree.

Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 8 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 2a2f6e869401..3e1506b808a3 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -31,6 +31,8 @@ static int max_hstate;
 unsigned int default_hstate_idx;
 struct hstate hstates[HUGE_MAX_HSTATE];
 
+__initdata LIST_HEAD(huge_boot_pages);
+
 /* for command line parsing */
 static struct hstate * __initdata parsed_hstate;
 static unsigned long __initdata default_hstate_max_huge_pages;
@@ -925,14 +927,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
 	return page;
 }
 
-static __initdata LIST_HEAD(huge_boot_pages);
-
-struct huge_bootmem_page {
-	struct list_head list;
-	struct hstate *hstate;
-};
-
-static int __init alloc_bootmem_huge_page(struct hstate *h)
+__attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h)
 {
 	struct huge_bootmem_page *m;
 	int nr_nodes = nodes_weight(node_online_map);